Evaluation of the International Society on Thrombosis & Haemostasis scoring system & its modifications in diagnosis of disseminated intravascular coagulation: A pilot study from southern India

BACKGROUND & OBJECTIVES: Diagnosis of disseminated intravascular coagulation (DIC) rests primarily on the clinical profile along with supportive laboratory tests. The International Society on Thrombosis and Haemostasis (ISTH) had proposed a scoring system for the diagnosis of overt DIC. However, fibrinogen values which are supposed to be low are often found to be elevated due to the associated inflammation seen in some cases. Moreover, peripheral smear is known to show schistocytes, which is also not included in the score. This study was done to evaluate ISTH scoring system and its modifications in suspected DIC. METHODS: Fifty-six patients were enrolled for the present study of whom; in four, fibrinogen assay could not be done. Modifications in the ISTH scoring with the exclusion of fibrinogen, i.e. modified ISTH (MI) score and subsequent inclusion of schistocytes, i.e. modified ISTH with schistocytes (MIS) score, were used. The modified scores were analyzed for diagnostic accuracy parameters and agreement with ISTH score. RESULTS: Amongst 56 cases, 9/52 (17.3%), 22 (39.3%) and 17 (30.4%) were diagnosed as positive for overt DIC by ISTH, MI and MIS scores and mortality was 33, 22.7 and 17.6 per cent, respectively. The sensitivity, specificity, positive and negative predictive values for the MI score were 100, 74.4, 45 and 100 per cent and for MIS score were 100, 86, 60 and 100 per cent, respectively. The agreement between MI score and MIS score with ISTH score was moderate [κ=0.502, 95% confidence interval (CI): 0.272-0.732, P<0.001] and substantial (κ=0.681, 95% CI: 0.45-0.91, P<0.001). INTERPRETATION & CONCLUSIONS: In the present study, the calculated mortality was highest by ISTH score. Best agreement was between MIS score and ISTH score. In a resource-constrained setup where fibrinogen assay and therefore ISTH score is difficult, it is suggested that MIS score can be considered.